Yet more than half of the planet's original forest cover has been lost or degraded and while land is left barren, the survival of entire communities, cultures and ecosystems remain under threat.

But there is huge potential to restore forests and turn degraded areas into healthy, fertile, working landscapes that meet the needs of people and the environment. And this restoration effort is well under way.

In 2011, an international assembly of high-level representatives from governments, businesses and conservation groups set a target to restore 150 million hectares of degraded lands by 2020. This agreement is called the Bonn Challenge.

The 50 million hectare mark – or one third of the target – is now within reach. In December 2012 Costa Rica and El Salvador were the latest to commit to restoring their degraded lands, joining USA, Rwanda and the Brazilian Mata Atlantica Restoration Pact.

During the UN Sustainable Development Rio +20 talks in 2012, more than one million people voted the Bonn Challenge as the second most important issue upon which heads of state should act.

To harness this public support, IUCN joined forces with Airbus to launch the Plant a Pledge campaign, which, through an online petition, empowers all people to call on governments, landowners and communities to contribute land to the Bonn Challenge. Plant a Pledge is backed by human rights and environmental campaigner Bianca Jagger.

Achieving the Bonn Challenge will deliver a host of major benefits to humanity and the planet, such as improving food security, protecting biodiversity and boosting people’s livelihoods.

Much more remains to be done though. Reaching the target will demand the success of dozens, possibly hundreds of landscape restoration projects around the world.

And it will take pledges of support from millions of people, businesses and organisations to put more pressure on governments to make it happen.

According to IUCN research, there are more than 1 billion hectares of lost or degraded forest lands worldwide which could be restored. This may increase to 1.5 billion hectares—almost the size of Russia—if boreal areas and forested protection of waterways and prevention of erosion in croplands are included.

International Day of Forests – 21 March is proclaimed by the United Nations to celebrate and raise awareness of the importance of all types of forests. On each International Day of Forests, countries are encouraged to undertake local, national and international efforts to organize activities involving forests and trees, such as tree planting campaigns.